Constitution of hexosediphosphoric acid. Part II

Abstract

THE researches of Harden and Young [1909, 1910] showed that the three monosaccharides glucose, mannose and fructose behave in the same way towards yeast juice in the presence of added phosphate.The identity of the hexosediphosphoric acid produced -in each case was established by Young [1909], who showed that this ester on acid hydrolysis yielded free phosphoric acid and a laevo-rotatory solution from which fructose could be isolated.The rotation of this solution, however, was always lower than that of a fructose solution of equal reducing power, and this caused Young to avoid drawing definite conclusions as to the nature of the sugar in hexosediphosphoric acid.Later Neuberg and Kretschmer [1911] succeeded in isolating crystalline fructose from the products of hydrolysis and they concluded that this was the only sugar present and that the original acid was fructosediphosphoric acid.At this time the reactive y-sugars had not been described, for it was not until some years later that Fischer [1914] prepared y-methylglucoside, the first representative of the structural isomerides containing an unstable oxide ring.The recognition that inulin and sucrose are derivatives of y-fructose followed from the work of Haworth [1920] and Irvine and Steele [1920] and in 1922 Menzies [1922] isolated y-methylfructoside from the products of esterification of ordinary fructose by Fischer's method.In the light of this more recent knowledge of structural isomerism in the sugar group the further investigation of the constitution of hexosediphosphoric acid was undertaken in order to determine the type of oxide ring in the hexose molecule as well as the position of the phosphoric acid groups.Of these two groups the position of one followed with considerable certainty from the work of Young [1911] on the reaction of hexosediphosphoric acid with phenylhydrazine.Using cold reagents he obtained the phenylhydrazine salt of a '1271